When the Contrail Actions item is selected in the Level Routines Window's
Actions to Perform column, the following set of controls appears in the
panel on the right side of the Level Routines window. These controls are
used to configure the contrail related actions that are carried out when
the selected routine is performed in the game.

Create Contrail Checkbox

Determines whether a contrail is created when the selected routine is performed

Contrail Type Pop-Up Menu

Determines which type of contrail is created when the selected routine is
performed. The Edit button may be used to edit the game project's contrail
types.

Create Contrail At Fixed Location Radio
Button

Determines whether a pair of fixed coordinates are used to determine the
location of the new contrail when the selected routine is performed

Contrail Location X and Y Fields

Determines the location of the new contrail

Use a Pair of Variables To Determine
Location Radio Button

Determines whether a pair of variables is used to set the location of the
new contrail when the selected routine is performed

Contrail Variable Location X and Y Bevel
Buttons

Determines which variables are used to set the location of the new contrail
when the selected routine is performed

Contrail Horizontal Speed Field

Determines the initial rightward speed of the contrail that is created when
the selected routine is performed

Contrail Downward Speed Field

Determines the initial downward speed of the contrail that is created when
the selected routine is performed

Only Create Contrail If Contrail Would
Be On Screen Checkbox

Determines whether the new contrail is only created if it would be on the
screen. This checkbox should be checked if this routine is performed often,
to prevent a huge number of contrails from being created while the player
is elsewhere.